Wednesday, December 14, 2011
The Oceans are Getting Warmer by Jennifer Donelson
The average temperature of the oceans has already increased significantly due to global warming and will continue to warm rapidly in coming decades. If we are going to effectively manage and conserve fish populations, we need to understand if (and how) these species will adjust to higher temperatures.
Unfortunately, our current understanding of how species might acclimate and adjust to rising temperatures is incomplete. A recent study completed by my colleagues and I will hopefully develop our understanding in this area.
Tropical species are expected to be among the groups most sensitive to environmental warming because they have evolved in a relatively stable thermal environment. In addition, “ectothermic” (cold-blooded) organisms – such as fish and lizards – are likely to be strongly impacted by rises in temperature since their body temperature varies directly with the environmental temperature.
Generally, we expect some capacity for acclimation and adaptation since we already know this occurs between populations. Differences in performance (the ability to function within the environment) can be observed between the same species living at different latitudes and therefore different temperature regimes.
But there is limited knowledge of whether species' evolutionary response to climate change will occur quickly enough to keep up with climate change. One way to approach this question is by running long-term experiments that simulate future conditions (as we did).